What a Means of Egress Cannot Pass Through

Why this matters

Almost every egress violation a field-service crew creates is created by someone who never touched a fire protection component. You set a pallet of filters in a corridor, you rehang a door so it swings the wrong way, you route the customer's back-of-house traffic through a stockroom that gets locked at night. None of that looks like fire protection work, and all of it can take a means of egress out of service. This card is deliberately written as a list of what a path may NOT pass through, because the affirmative version ("provide adequate egress") is what people already think they are doing when they get it wrong.

Three legs, and only one of them is protected

A means of egress is a continuous and unobstructed path of travel from any point in a building to a public way. It has three legs, and they are not interchangeable. NFPA 101, in the edition your authority having jurisdiction has adopted and amended, calls them exit access, exit, and exit discharge. The federal floor uses the same three-part structure under the term "exit route" at 29 CFR 1910.34 and 1910.36. The authority having jurisdiction is a named role with legal authority to interpret and enforce the adopted code, usually the fire marshal or building official, and not a synonym for whoever happens to be inspecting.

The middle leg is the one that carries fire-resistance-rated protection. That is the whole reason the legs are named separately, and it is why a question like "can the path go through here" has three different answers depending on where you are standing.

  workroom corridor stair yard
    o------------o---------------o--------------o--> public way
    |            |               |              |
    exit access exit access     EXIT           exit discharge
    (unprotected, travel-limited) (rated enclosure) (to a public way)

  The rated enclosure starts at the stair door and ends
  where the stair lets out. Nothing that is not the stair
  is allowed inside that boundary.

What the exit access may not pass through

Exit access is the travel from where you are to the door of the exit. It is normally unprotected, so the code controls it by limiting travel distance, common path and dead ends, and by restricting what you can travel through.

• Any space subject to locking against egress. The adopted model building code prohibits egress through kitchens, storage rooms, closets and spaces used for similar purposes, and NFPA 101 in the adopted edition reaches the same result through its intervening-space and hazardous-area rules. Both bind where both are adopted, and the enumeration is the building code's. A stockroom with a keyed knob is the single most common field version of this, and it is created by a shop installing hardware, not by a designer.
• A room that is not accessory to the space it serves. Travel through an intervening room is limited to a room that belongs to the same tenant and function. A path from one tenant's back room through another tenant's floor is not exit access, it is a courtesy that will not exist on the worst day.
• Anything that narrows the required clear width. The narrowest point governs the whole path, not the average. 29 CFR 1910.36 sets the federal floor at not less than 28 inches wide at all points and not less than 7 feet 6 inches of ceiling height, and 1910.37(a) requires exit routes to be kept free and unobstructed with no materials or equipment placed in them. Your adopted building code will usually require more width than 28 inches based on occupant load; where both apply, the more demanding one governs and the AHJ owns the interpretation.

What the exit itself may not pass through

Once you are inside the exit, you are inside a rated enclosure, and the rule collapses to one sentence: nothing that is not part of the exit belongs in it.

That single rule generates most of the findings written on a stair. No storage, not even briefly. No fuel-fired equipment and no fuel piping serving anything other than the stair. No penetrations except those serving the enclosure itself, and any penetration made for a cable pull or a conduit run has to be restored with a firestop system tested for that exact assembly and that exact penetrant. No openings other than the rated doors, and those doors are opening protectives governed by NFPA 80 in the edition the AHJ adopted, which is where the annual fire door inspection requirement lives.

The failure mode here is delayed and quiet. A low-voltage tech pulls four cables through a stair wall on a Tuesday, foams the hole because foam looks like firestop, and the enclosure is compromised for years. Nobody notices, because a stair enclosure does nothing visible until the day it is holding smoke out of the one path everybody is using.

What the exit discharge may not pass through

Discharge is the leg from the exit to a public way. Its restrictions are the ones most often defeated by ordinary site operations.

• It may not dead-end in a controlled yard. Discharging into a fenced compound whose gate is padlocked after hours converts an exit into a trap. 29 CFR 1910.36(e) requires the discharge to lead directly outside or to a street, walkway, refuge area, public way, or open space with access to the outside, and the space has to be large enough for the building occupants likely to use it.
• It may generally not run back through the building interior, except under a limited allowance in the adopted code that permits a percentage of exits to discharge through a level of exit discharge only where specific conditions are met: the path is direct and obvious, the level is sprinklered, and the discharge area is separated from the rest of the level. The percentage and the conditions belong to the adopted edition, so route that one to the AHJ rather than assuming your building qualifies.
• It may not depend on snow, ice, landscaping, or parking to stay usable. A discharge path that works in July and disappears under a plow berm in January is not a compliant path in January.

The width that quietly is not there

Clear width is measured between the most restrictive projections, at the height where a person's body actually is, with the door in its worst position. Three things eat it and none of them show on a drawing: a door leaf swinging into the path and stopping partway, a wall-mounted item projecting into the corridor, and stored material that arrived as a temporary staging decision. Measure the narrowest point with a tape, not by eye. Corridor width is the field measurement most often estimated and most often wrong, because a corridor that reads as generous at eye level can be pinched at knee height by a rack base.

Worked example: one tenant suite, one path, four findings

A single-story sprinklered strip building. A service company is called in to add a rooftop unit and, while they are there, the tenant asks them to "tidy up" the back-of-house. The occupied workroom at the rear has one path out. Walk it as three legs.

Leg 1, exit access. From the workroom the path goes through a stockroom, then into a corridor, then to the rear door. Two findings live in this leg. The stockroom carries a keyed lockset on the corridor side, so the path passes through a space subject to locking, which the adopted NFPA 101 prohibits for exit access. And in the corridor, the measured clear width is 44 inches at the wall, reduced to 26 inches by a rolling rack the tenant staged there three weeks ago. Twenty-six inches is below the 28-inch federal floor at 29 CFR 1910.36 before you even get to the width the adopted building code requires for the occupant load, so it fails on the lower of the two numbers.

Leg 2, exit. There is no rated enclosure in this path at all. In a single-story building the door to the outside is the exit, and it has no enclosure to compromise. That is worth stating rather than skipping, because a crew that has learned the stair rules sometimes goes looking for an enclosure that does not exist, and a crew that has not sometimes applies stair rules to a corridor that never had them.

Leg 3, exit discharge. The rear door opens into a fenced service yard. The yard gate is chained after 6 pm. Everyone in the shop knows the code to the front door and nobody knows where the gate key lives. Under 29 CFR 1910.36(e) the discharge has to reach a street, walkway, or open space with access to the outside; a chained gate ends the path short of that.

Fourth finding, the one the crew created. The rooftop work required a chase penetration through the corridor ceiling into the demising wall. The apprentice filled it with expanding foam. The wall is rated construction, so the penetration needs a firestop system tested for that assembly and that penetrant.

Correction, printed: clear width 44 in as-built, minus the rack, restored to 44 in, against a 28 in federal floor and whatever the adopted code sets for occupant load, which is the number that actually governs. Stockroom lockset swapped to hardware that always releases from the egress side in one motion, which the sibling card on locked exit doors owns. Yard gate converted to panic hardware or the discharge re-routed. Foam removed and replaced with a tested firestop system.

The two same-trip items, pulling the rack out of the corridor and stripping the foam back out of the penetration, ran under 2 labor hours. The lockset change, the tested firestop system and the gate hardware are ordered work with lead time, and none of them closed on the same trip. The crew found it on the same trip. Catching it after the AHJ did would have cost a second mobilization plus a re-inspection wait, a multiple of roughly 3 to 4 times the correction time, and the shop's name on the correction notice.

Sibling-rule check. Run this scenario against the other rules this group states. The stockroom hardware is resolved to a listed always-releases arrangement rather than "we will leave it unlocked," which is what the locked-exit card requires. The path's illumination and marking are not asserted as compliant here, because the emergency and exit lighting card owns the duration test that proves it. No claim is made that the corridor is protected, because nothing in this path is an exit enclosure. The firestop restoration is written as a tested system for the specific assembly, not as a material.

Verifying it on your own jobs

Walk the path in the direction an occupant would run, at night, without turning on lights you would not have. Carry a tape. At each leg boundary say out loud which leg you are entering, because the restrictions change at that line and nowhere else. Then write down the narrowest measured width, the location of every door that swings into the path, every lockable space you passed through, and every penetration your own crew made that day. If your record does not name the leg, it will not be readable by the person who reads it a year from now.

References

• 29 CFR 1910.34, 1910.36 and 1910.37, exit route definitions, design and maintenance in general industry; 29 CFR 1926 Subpart F for construction work
• NFPA 101 Life Safety Code, in the edition adopted and amended by your authority having jurisdiction, for exit access travel restrictions and exit discharge allowances
• NFPA 80, Standard for Fire Doors and Other Opening Protectives, in the adopted edition, for door and opening requirements inside a rated enclosure
• See related: Why a Locked Exit Door Is the Oldest Fatal Mistake; What Emergency and Exit Lighting Have to Do